PHYSIOGRAPHY. 



Cleavage, distinct parallel to M and to T 9 also in 

 the direction of a plane which takes away the 

 more obtuse edge between M and T ; this plane 

 intersects M at an angle of 144 3', and T at 

 an angle of 130 33'. 



Massive : composition granular. Fracture earthy. 



Lustre resinous. Colour white, sometimes greenish. 

 Translucent on the edges ... opake. 



Hardness 3*5 . . . 4-0. It seems to become harder 

 by exposure to the air. Sp. Gr. = 2-55 ... 2-60. 



When reduced to powder it phosphoresces with a blueish 

 light. Before the blowpipe it first becomes black, then 

 white, afterwards intumesces and melts on its edges. With 

 borax it yields a transparent glass. According to NOHDEN- 

 SKIOLD, from whom the whole of the preceding description 

 is taken, it consists of 



Silica 56-62. 



Magnesia 23-38. 



Alumina 3-38. 



Lime 5-58. 



Oxide of Iron 0-99. 



Protoxide of Manganese 0-99. 



Water 3-58. 



. leaving 6-38 of an unknown bituminous substance and loss. 

 It occurs at Storgard in the parish of Pargas in Finland, 

 with several species of the genera Feld-spar and Augite- 

 spar ; also with prismatic Titanium-ore and rhombohedral 

 Lime-haloid e. 



PYRORTHITE. 



Pyrorthit. BERZEXIUS. Afhandl. i Fysik, &e. Vol. V. 

 Pyrorthite. PHILL. p. 265. 



Probably prismatic. Massive : composition colum- 

 nar. Fracture cqnehoidal, splintery, earthy. 



